JP2016538758A - Method and apparatus for optimizing the coverage area of a small cell - Google Patents

Abstract

The present disclosure presents a method and apparatus for optimizing a small cell coverage area. For example, the present disclosure includes estimating a small cell's available backhaul capacity and determining a small cell's target OTA data rate based at least on the estimated available backhaul capacity. And a method for changing the coverage area of a small cell based at least on the determined target OTA data rate. In this way, the optimization of the coverage area of a small cell can be achieved.

Description

This patent application is assigned to the “Method and Apparatus for Optimizing Coverage Area of a Small” filed on April 3, 2014, assigned to the assignee of the present application and expressly incorporated herein by reference. US Provisional Patent Application No. 14 / 244,152 entitled “Cell” and US Provisional Patent Application No. 61 / 892,987 entitled “Apparatus and Method for Optimizing Coverage Area of a Small Cell” filed on October 18, 2013. And insist on priority.

  The present disclosure relates generally to communication systems, and more particularly, to methods and apparatus for optimizing small cell coverage areas.

  Wireless communication systems are widely deployed to provide various telecommunication services such as telephone, video, data, messaging, and broadcast. A typical wireless communication system can utilize multiple access technologies that can support communication with multiple users by sharing available system resources (eg, bandwidth, transmit power). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier Frequency division multiple access (SC-FDMA) systems and time division synchronous code division multiple access (TD-SCDMA) systems are included.

  These multiple access technologies are employed in various telecommunications standards to provide a common protocol that allows various wireless devices to communicate on a local, national, regional and even global scale. An example of an emerging telecommunications standard is Long Term Evolution (LTE). LTE is an extension set to the Universal Mobile Telecommunications System (UMTS) mobile standard published by the 3rd Generation Partnership Project (3GPP). LTE supports mobile broadband Internet access better by improving spectrum efficiency, lowering costs, improving services, utilizing new spectrum, and OFDMA on the downlink (DL), Designed to do better integration with other open standards using SC-FDMA on the uplink (UL) and multi-input multi-output (MIMO) antenna technology. However, as demand for mobile broadband access continues to increase, further improvements in LTE technology are needed. Preferably, these improvements should be applicable to other multiple access technologies and telecommunications standards that utilize these technologies.

  To supplement traditional base stations, additional limited power, or limited coverage base stations called small coverage base stations or cells, can be deployed to provide more robust wireless coverage to mobile devices. . For example, wireless relay stations and low power base stations (e.g., typically home NodeB or home) for incremental capacity increase, richer user experience, within buildings or other specific geographic areas, and / or the like may be called eNB, and collectively called H (e) NB, femto node, pico node, etc.). Such low-power or small-scale coverage (e.g., compared to a macro network base station or cell) base stations have broadband connections (e.g., digital subscriber line (DSL) routers, cables, or other modems). May be connected to the Internet via the Internet and may provide a backhaul link to the mobile operator's network. Thus, for example, a small coverage base station may be deployed in a user's home to provide mobile network access to one or more devices via a broadband connection. Since deployment of such base stations is unplanned, low power base stations may interfere with each other if multiple stations are deployed in the vicinity of each other.

  In some small cell deployments, such as neighboring small cells, the backhaul may be limited with respect to maximum supported throughput. However, in such deployments, over-the-air (OTA) data rates supported by small cells may exceed the backhaul capacity of small cells and result in inefficient use of OTA resources.

  Accordingly, a method and apparatus for optimizing the coverage area of a small cell is desired.

  Next, various aspects will be described with reference to the drawings. In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It will be apparent, however, that such embodiments can be practiced without these specific details. The following presents a simplified summary of such aspects in order to provide a basic understanding of one or more aspects.

  The present disclosure presents exemplary methods and apparatus for optimizing a small cell coverage area. For example, the present disclosure includes estimating a small cell's available backhaul capacity and determining a small cell's target OTA data rate based at least on the estimated available backhaul capacity. And changing the coverage area of the small cell based at least on the determined target OTA data rate.

  In an additional aspect, an apparatus for optimizing a small cell coverage area is disclosed. The apparatus determines a target OTA data rate for a small cell based at least on the means for estimating the available backhaul capacity of a small cell and the estimated available backhaul capacity. And means for changing the coverage area of the small cell based at least on the determined target OTA data rate.

  In a further aspect, a computer program product for optimizing a small cell coverage area is described. The computer program product estimates an available backhaul capacity for a small cell and determines a target OTA data rate for the small cell based at least on the estimated available backhaul capacity. And a computer readable medium comprising code executable by the computer to change the coverage area of the small cell based at least on the determined target OTA data rate.

  Furthermore, the present disclosure presents an apparatus for optimizing a small cell coverage area. The apparatus includes a backhaul capacity estimation component for estimating the available backhaul capacity of a small cell and a target OTA of the small cell based at least on the estimated available backhaul capacity. A target OTA data rate determination component for determining the data rate and a parameter optimization component for changing the coverage area of the small cell based at least on the determined target OTA data rate.

  To the accomplishment of the above and related ends, one or more aspects include the features fully described below and specifically pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. However, these features are merely illustrative of some of the various ways in which the principles of various aspects may be utilized, and this description is intended to include all such aspects and their equivalents.

1 is a block diagram illustrating an example wireless system in aspects of the present disclosure. FIG. FIG. 3 is a block diagram illustrating an example coverage optimization manager in aspects of the present disclosure. 6 is a flow diagram illustrating aspects of a method for distributed optimization of a self-organizing network. FIG. 3 is a block diagram illustrating aspects of a logical grouping of electrical components contemplated by the present disclosure. FIG. 1 illustrates an example communication system for enabling deployment of small cells in a network environment. FIG. 6 is a block diagram illustrating aspects of a computing device according to the present disclosure. FIG. 6 is a block diagram illustrating an example of a hardware implementation for an apparatus employing a processing system. 1 is a block diagram conceptually illustrating an example of a telecommunications system. FIG. It is a conceptual diagram which shows the example of an access network. It is a block diagram which shows notionally the example of NodeB which is communicating with UE in a telecommunication system.

  The following detailed description of the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

  The present disclosure presents exemplary methods and apparatus for optimizing a small cell coverage area. For example, the data rate supported by a small cell may be limited by the available backhaul capacity of the small cell. Thus, a target over-the-air (OTA) data rate based at least on the estimated available backhaul capacity is determined, and the coverage area for small cells is usually more areas and / or not covered by small cells. Or changed (eg, increased) to cover the UE.

  With reference to FIG. 1, illustrated is a wireless communication system 100 that facilitates optimizing a small cell coverage area.

  In certain aspects, for example, system 100 may include one or more base stations, eg, small cells 110 that are in communication with core network entity 102 via one or more communication links, eg, link 104. It can be a communication network. System 100 may include one or more user terminals, eg, UEs 122 in coverage area 120 of small cell 110. UE 122 may communicate with small cells via one or more over the air (OTA) links 116. FIG. 1 shows a plurality of UEs 122 in the coverage area 120 of the small cell 110.

  As used herein, the term “small cell” refers to a relatively low transmit power and / or a relatively small coverage area cell compared to the transmit power and / or coverage area of a macro cell. Point to. Further, the term “small cell” may include, but is not limited to, a cell such as a femto cell, a pico cell, an access point base station, a home NodeB, or a femto access point. For example, a macrocell can cover a relatively large geographic area, such as but not limited to a few kilometers in radius. In contrast, a picocell can cover a relatively small geographic area such as, but not limited to, a building. Further, femtocells can also cover a relatively small geographic area, such as, but not limited to, a residence or a floor of a building.

  In an aspect, the small cell 110 may be configured with a coverage optimization manager 112. Coverage optimization manager 112 facilitates optimizing the coverage area of small cell 110. The coverage optimization manager 112 estimates the available backhaul capacity for the small cell and determines the target OTA data rate for the small cell based at least on the estimated available backhaul capacity. And the small cell coverage area may be optimized by changing the small cell coverage area based at least on the determined target OTA data rate.

  In additional aspects, the coverage optimization manager 112 may be configured to include a parameter optimization component 114. The parameter optimization component 114 changes, eg, increases or decreases, the small cell coverage area by modifying one or more parameters of the small cell. For example, in an aspect, the coverage optimization manager 112 may increase the small cell coverage area from the coverage area 120 to the coverage area 130 by modifying one or more parameters of the small cell. In some aspects, the parameters modified to increase (or decrease) the coverage area of a small cell include: small cell transmit power, number of small cell resource elements, pilot channel transmit power, The cell's operating bandwidth, traffic to pilot ratio, etc. may be included and are described in detail below.

  In additional or optional aspects, for example, the coverage optimization manager 112 reduces the small cell coverage area from the coverage area 120 to the coverage area 140 by modifying one or more parameters of the small cell. Can be. For example, in an aspect, the coverage area of small cell 110 may be reduced when it is determined that the available backhaul capacity can support a higher over-the-air (OTA) data rate at the UE.

  With reference to FIG. 2, an exemplary coverage optimization manager in an aspect of the present disclosure is shown.

  In an aspect, for example, the coverage optimization manager 112 of the small cell 110 is configured to include a backhaul capacity estimation component 210, a target OTA data rate determination component 212, and / or a parameter optimization component 114. Can be done.

  In an aspect, the backhaul capacity estimation component 210 can be configured to estimate the available backhaul capacity of a small cell. For example, in an aspect, the backhaul capacity estimation component 210 of the small cell 110 is used by the small cell 110 to communicate with the core network entity 102 to support one or more UEs 122. It may be configured to estimate the available capacity of the link 104.

  The backhaul capacity of the small cell 110 available for the UE 122 may depend on various factors. For example, in an aspect, link 104 may be shared with other wired / wireless devices on a small cell, eg, a Wi-Fi router, set-top box, Wi-Fi TV, etc., thereby for UE 122 Reduce available backhaul capacity. In additional aspects, the link 104 may encounter congestion that may affect the backhaul capacity available to support the UE 122. In yet additional aspects, the backhaul capacity available for UE 122 may depend on the type of backhaul, eg, fiber, digital subscriber line (DSL), cable modem, Ethernet, etc.

  In certain aspects, the available capacity of the backhaul may be estimated using a number of techniques. For example, in certain aspects, the available capacity of the backhaul (eg, link 104) may be estimated using light probing or heavy probing. In an additional aspect, the available capacity of the backhaul can be estimated by initiating a small download session via link 104 from a known server. In yet additional aspects, for example, the available capacity of the backhaul 104 can be estimated by measuring a round trip time (RTT) delay.

  In an aspect, the target OTA data rate determination component 212 may be configured to determine a small cell target OTA data rate based at least on the estimated available backhaul capacity. For example, in certain aspects, target OTA data rate determination component 212 may determine a target OTA data rate for small cell 110 based on the estimated available capacity of link 104.

  For example, in one aspect, if the estimated available backhaul capacity is 10 Mbps, the target OTA data rate determination component 212 determines the target OTA data rate for small cells to be a value of 10 Mbps or less. As such, small cells may not be able to support data rates above 10 Mbps due to backhaul limitations. When the target OTA data rate is set to a value exceeding 10 Mbps, the small cell OTA resources are not used efficiently. In additional or optional aspects, the peak OTA data rate may be identified based on the small cell configuration. For example, in an aspect, the peak OTA data rate supported by a small cell may be determined based on the number of antennas and / or antenna configuration of the small cell.

  In an aspect, the parameter optimization component 114 may modify the small cell coverage area based on the determined target OTA data rate by modifying one or more parameters of the small cell. Can be configured. For example, in an aspect, the coverage area of the small cell 110 may be changed based on the determined target OTA data rate by modifying one or more parameters of the small cell.

  For example, the transmit power per small cell resource element (RE) may be increased to increase the coverage area of the small cell. Increased transmit power per RE for small cells provides enhanced coverage to allow small cells to serve UEs that would otherwise be outside the coverage of small cells. obtain. For example, the coverage area 130 of FIG. 1 illustrates an aspect in which the coverage area of a small cell is increased, for example, by increasing the transmit power per RE of a small cell, and then one service or It may be possible to provide to multiple UEs 132.

  In one aspect, the small cell may incur all REs anyway due to backhaul limitations, as the transmit power per RE of a small cell increases, the number of resource elements in the small cell may decrease. May not be available. In an additional aspect, this may allow an increase in the coverage area of the small cell by increasing the transmission power of the small cell. For example, the cell coverage area is increased by increasing the transmit power on the reduced set of available REs in combination with increasing the power of the common channel without changing the total radiated power over the entire bandwidth. obtain.

  In an exemplary aspect, the carrier operating bandwidth of a small cell may be changed. For example, a small cell may operate with a 10 MHz or 20 MHz carrier, and the operating carrier bandwidth may be changed to a 5 MHz carrier. This is only an example and not a limitation, as small cells may operate on carriers with any size bandwidth. In an aspect, the carrier bandwidth of a small cell may be reduced to increase the small cell coverage area by increasing the power available on the RE.

  In additional exemplary aspects, the operating bandwidth of the small cell carrier may be modified based on operational measurements (OM) collected in the small cell. For example, if a small cell decides that the coverage area of a small cell can be increased by providing more available power to the RE based on information obtained from the collected OM, the small cell May reduce the operating bandwidth of the carrier based on the OM collected by the small cell.

  In additional or any exemplary aspects, the small carrier's operating carrier bandwidth may be configured when the small cell is first turned on or after initial setup. In addition, network operators can pre-set (eg, 5 MHz, 10 MHz, 20 MHz, etc.) various carrier bandwidths that can be set in a small cell.

  In an aspect, the common channel and / or pilot transmit power may be increased / decreased to support increased / reduced coverage areas for small cells. For example, in an aspect, when the transmission power of the common channel is increased, the common channel can be, for example, a common reference signal (CRS), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel ( PBCH), and physical downlink control channel (PDCCH). To support an extended coverage area for small cells, the common channel / pilot transmit power may be increased.

  In additional aspects, traffic to pilot (T2P) values, eg, Pa / Pb, may be increased / decreased to increase / decrease the coverage area of small cells. In certain aspects, the target number of hybrid automatic repeat request (HARQ) transmissions may be increased. For example, for a given transmit power, if the target number of HARQ transmissions is increased from 1 to 4 transmissions, a gain of 6 dB may be achieved to increase the coverage area of small cells. Further, in certain aspects, the block error rate (BLER) target of the HARQ process may be increased to increase the coverage range of small cells.

  Furthermore, various parameters can be modified in the small cell to change the coverage range of the small cell. For example, in order to maintain the total transmission power below the maximum allowable power, the aggregation level of PDCCH is adjusted to limit the number of PDCCH and PDSCH resource blocks (RB). For example, if the pilot or control channel is boosted to improve the coverage area of a small cell, the PDSCH transmit power may be reduced or compensated for the PDSCH to compensate for the increase in pilot / overhead / control channel power The number of RBs used for can be reduced. In an aspect, when the transmission power of the common channel is increased, the peak OTA data rate of the small cell may decrease because the power is borrowed from the total power.

  In certain aspects, modifying the parameters of the small cell may be semi-static or dynamic. For example, the parameters can be dynamically modified based on the estimated available backhaul capacity. In any aspect, the parameters may be configured in a semi-static manner, for example, small cell configuration aspects such as time of day, number of users served by the small cell, small cell deployment density, UE capabilities, and MIMO configuration. Can be modified based on A semi-static approach can be used to avoid frequent changes in the coverage area of small cells.

  In an aspect, the small cell parameters may be modified to a small cell bias configuration towards increasing the small cell coverage or meeting the target OTA data rate. For example, if more UEs are outside the small cell coverage area, the parameters may be modified to increase the small cell coverage area. In an additional exemplary aspect, if more UEs are closer to the center of the small cell, the parameter can be used to reduce the coverage area of the small cell by reducing the transmission power of the small cell. May be modified, thus allowing small cells to support higher OTA data rates.

  In any aspect, if it is determined that more UEs are located closer to the center of the small cell rather than the edge of the cell or outside the cell coverage area, the transmission power of the small cell is Can be reduced. By reducing the coverage area of a cell, a small cell can support more UEs present in the reduced coverage area and / or provide a higher peak data rate.

  FIG. 3 illustrates an example method 300 for optimizing a small cell coverage area. In an aspect, at block 302, the method 300 may include estimating an available backhaul capacity for a small cell. For example, in an aspect, the base station 110, and / or the coverage optimization manager 112, and / or the backhaul capacity estimation component 210 are configured to estimate the available backhaul capacity of a small cell. obtain. For example, the available backhaul capacity may depend on multiple factors as described above.

  Further, at block 304, the method 300 may include determining a target OTA data rate for the small cell based at least on the estimated available backhaul capacity. For example, in an aspect, the base station 110, and / or the coverage optimization manager 112, and / or the target OTA data rate determination component 212 may be based on at least the estimated available backhaul capacity, May be configured to determine a target OTA data rate.

  Further, at block 306, the method 300 may include changing the coverage area of the small cell based at least on the determined target OTA data rate. For example, in an aspect, the base station 110, and / or the coverage optimization manager 112, and / or the parameter optimization component 114 may change the small cell coverage area based at least on the determined target OTA data rate. Can be configured to. In additional or optional aspects, for example, the step of changing the coverage area of a small cell based at least on the determined target OTA data rate may be performed as described above with reference to FIG. It may include modifying one or more parameters of the cell.

  Referring to FIG. 4, an exemplary system 400 for optimizing a small cell coverage area is displayed. For example, system 400 may reside at least partially within small cell 110 (FIG. 1). It should be appreciated that system 400 is represented as including functional blocks, which may be functional blocks that represent functions performed by a processor, software, or combination thereof (eg, firmware). System 400 includes a logical grouping 402 of electrical components that can act in conjunction. For example, the logical grouping 402 may include an electrical component 404 for estimating the available backhaul capacity of a small cell. In an aspect, the electrical component 404 can comprise a backhaul capacity estimation component 210 (FIG. 2).

  Further, the logical grouping 402 may include an electrical component 406 for determining a small cell target OTA data rate based at least on the estimated available backhaul capacity. In an aspect, the electrical component 406 can comprise a target OTA data rate determination component 212 (FIG. 2). Further, in an aspect, the logical grouping 402 may include an electrical component 408 for changing a small cell coverage area based at least on the determined target OTA data rate. In certain aspects, the electrical component 408 may comprise a parameter optimization component 114 (FIGS. 1-2).

  Further, the system 400 retains instructions for performing functions associated with the electrical components 404, 406, and 408, and stores data used or obtained by the electrical components 404, 406, and 408. A memory 410 may be included that performs storage and the like. Although electrical components 404, 406, and 408 are shown as being external to memory 410, one or more of these electrical components can be present in memory 410. I want you to understand. In one example, electrical components 404, 406, and 408 can include at least one processor, or each electrical component 404, 406, and 408 can be a corresponding module of at least one processor. Can do. Further, in additional or alternative examples, electrical components 404, 406, and 408 can be computer program products that include computer-readable media, with each electrical component 404, 406, and 408 correspondingly. It can be a code.

  FIG. 5 shows an exemplary communication system for enabling deployment of base stations in a network environment. As shown in FIG. 5, system 500 includes multiple base stations, such as HNB 510, or home Node B units (HNBs), or small cells, each of which has a residence 530 of one or more users, for example. In a corresponding small scale network environment and configured to serve related as well as heterogeneous user equipment (UE) 520. Each HNB 510 is further coupled to the Internet 540 and the mobile operator's core network 550 via a DSL router (not shown) or alternatively via a cable modem (not shown).

  The embodiments described herein use 3GPP terminology, but the embodiments use 3GPP (Rel99, Rel5, Rel6, Rel7) techniques, and 3GPP2 (1xRTT, 1xEV-DO Rel0, RevA, RevB) techniques, as well as other known And it should be understood that it can be applied to related techniques. In such aspects described herein, the owner of the HNB 510 subscribes to a mobile service, such as, for example, a 3G mobile service provided through the mobile operator's core network 550, and the UE 520 has a macro cellular environment and It can operate both in residential small scale network environments. Thus, the HNB 510 is backward compatible with any existing UE 520.

  Further, in addition to the macro cell mobile network 550, the UE 520 may only be served by a predetermined number of HNBs 510, i.e., HNBs 510 present in the user's residence 530, and will not be in soft handover with the macro network 550. Can not. UE 520 can communicate with either macro network 550 or HNB 510, but not both at the same time. As long as UE 520 is allowed to communicate with HNB 510, within the user's residence, UE 520 is desired to communicate only with the associated HNB 510.

  Referring to FIG. 6, in one aspect, one or more of the small cells 110 (FIG. 1) including the coverage optimization manager 112 (FIGS. 1-2) are specially programmed or configured computers. It may be represented by device 600. In one aspect of an implementation, the computing device 600 includes a coverage optimization manager 112 (FIGS. 1-2), such as in specially programmed computer readable instructions or code, firmware, hardware, or some combination thereof. obtain. Computer device 600 includes a processor 602 for performing processing functions associated with one or more of the components and functions described herein. The processor 602 may include a single set or multiple sets of processors or multi-core processors. Moreover, the processor 602 may be implemented as an integrated processing system and / or a distributed processing system.

  The computing device 600 further includes a memory 604, such as for storing data and / or local versions used herein for applications being executed by the processor 602. Memory 604 can be any type of memory that can be used by a computer, such as random access memory (RAM), read only memory (ROM), tape, magnetic disk, optical disk, volatile memory, non-volatile memory, and any combination thereof. Can be included.

  In addition, the computing device 600 can utilize hardware, software, and services to establish and maintain communication with one or more parties as described herein Contains element 606. Communication component 606 communicates between components on computer device 600, and external such as computer device 600, a device located on a communication network, and / or a device connected in series or locally to computer device 600. Communication between devices can be communicated. For example, the communication component 606 may include one or more buses and is operable to interface with external devices and is associated with a transmitter and a receiver respectively associated with a transmitter chain and a receiver chain component Or a transceiver. In additional aspects, the communication component 606 can be configured to receive one or more pages from one or more subscriber networks. In a further aspect, such a page may correspond to a second subscription and may be received via a first technology type communication service.

  In addition, the computing device 600 may further include a data storage device 608 that provides mass storage of information, databases, and programs utilized in connection with aspects described herein. Can be any suitable combination of hardware and / or software. For example, data storage device 608 may be a data repository for applications that are not currently being executed by processor 602 and / or any threshold or finger position values.

  The computing device 600 may further include a user interface component 610 operable to receive input from a user of the computing device 600 and further operable to generate output for presentation to the user. User interface component 610 includes, but is not limited to, a keyboard, number pad, mouse, touch sensitive display, navigation keys, function keys, microphone, voice recognition component, and any other capable of receiving input from the user. One or more input devices, including any of these mechanisms, or any combination thereof. Further, user interface component 610 includes one that includes, but is not limited to, a display, speaker, haptic feedback mechanism, printer, any other mechanism capable of presenting output to the user, or any combination thereof. Or it may include multiple output devices.

  FIG. 7 illustrates an apparatus 700 that includes the coverage optimization manager 112 of FIG. 1 that employs a processing system 714 to perform aspects of the present disclosure, such as, for example, a method for optimizing a coverage area of a small cell. It is a block diagram which shows the example of the hardware mounting form. In this example, processing system 714 may be implemented with a bus architecture generally represented by bus 702. Bus 702 may include any number of interconnecting buses and bridges, depending on the specific application of processing system 714 and the overall design constraints. Bus 702 is typically one or more processors represented by processor 704, a computer readable medium generally represented by computer readable medium 706, and, but is not limited to, coverage optimization manager 112 (FIGS. 1-2). Link various circuits including one or more components described herein. Bus 702 can also link a variety of other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore no more. Will not be explained. Bus interface 708 provides an interface between bus 702 and transceiver 710. The transceiver 710 provides a means for communicating with various other devices on the transmission medium. Further, a user interface 712 (for example, a keypad, a display, a speaker, a microphone, a joystick, etc.) may be provided depending on the nature of the device.

  The processor 704 is responsible for general processing including management of the bus 702 and execution of software stored on the computer readable medium 706. The software, when executed by the processor 704, causes the processing system 714 to perform various functions described below for any particular device. The computer readable medium 706 may be used for storing data that is manipulated by the processor 704 when executing software.

  FIG. 8 includes one or more small cells employing various devices of the wireless communication system 100 (FIG. 1) and configured to include a coverage optimization manager 112 (FIGS. 1-2). FIG. 1 shows a resulting Long Term Evolution (LTE) network architecture 800. The LTE network architecture 800 may be referred to as an evolved packet system (EPS) 800. EPS800 consists of one or more user equipment (UE) 802, evolved UMTS terrestrial radio access network (E-UTRAN) 804, evolved packet core (EPC) 880, home subscriber server (HSS) 820, and operator IP services 822 may be included. EPS can interconnect with other access networks, but for simplicity, their entities / interfaces are not shown. As illustrated, EPS provides packet switched services, but those skilled in the art will readily understand that the various concepts presented throughout this disclosure can be extended to networks that provide circuit switched services. I will.

  E-UTRAN includes evolved Node B (eNB) 806 and other eNB 808. The eNB 806 provides user and control plane protocol termination towards the UE 802. The eNB 808 may be connected to other eNB 808 via an X2 interface (ie, backhaul). eNB806 is also used by those skilled in the art to base station, base transceiver station, radio base station, radio transceiver, transceiver function, basic service set (BSS), small cell, extended service set (ESS), or some other appropriate terminology. Can be called. The eNB 806 provides the UE 802 with an access point to the EPC 880. Examples of UE802 include cellular phones, smartphones, session initiation protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video devices, digital audio players (e.g. MP3 player), camera, game console, or some other similar functional device. UE802 is also available by those skilled in the art to mobile stations, subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile It may be referred to as a terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or other appropriate terminology.

  The eNB 806 is connected to the EPC 880 via the S1 interface. The EPC 880 includes a mobility management entity (MME) 862, another MME 864, a serving gateway 866, and a packet data network (PDN) gateway 868. The MME 862 is a control node that processes signaling between the UE 802 and the EPC 880. In general, MME 862 provides bearer and connection management. All user IP packets are forwarded through the serving gateway 866, which itself is connected to the PDN gateway 868. PDN gateway 868 provides UE IP address assignment as well as other functions. The PDN gateway 868 is connected to the operator's IP service 822. Operator IP services 822 include the Internet, Intranet, IP Multimedia Subsystem (IMS), and PS Streaming Service (PSS).

  Referring to FIG. 9, an access network 900 within the UTRAN architecture is shown and includes one or more base stations or small cells configured to include a coverage optimization manager 112 (FIGS. 1-2). May be included. A multiple access wireless communication system includes multiple cellular regions (cells) including cells 902, 904, and 906, each of which can include one or more sectors. The multiple sectors may be one or more small cells 110 of FIG. Multiple sectors may be formed by groups of antennas, each antenna responsible for communication with UEs that are part of the cell. For example, in cell 902, antenna groups 912, 914, and 916 may each correspond to a different sector. In cell 904, antenna groups 918, 920, and 922 each correspond to a different sector. In cell 906, antenna groups 924, 926, and 928 each correspond to a different sector. Cells 902, 904, and 906 may be in communication with one or more sectors of each cell 902, 904, or 906, eg, several wireless, including UEs 122, 132, and 142 of FIG. It may include communication devices such as user equipment or UEs. For example, UEs 930 and 932 may be communicating with NodeB 942, UEs 934 and 936 may be communicating with NodeB 944, and UEs 938 and 940 may be communicating with NodeB 946. Here, each NodeB 942, 944, 946 is configured to provide an access point for all UEs 930, 932, 934, 936, 938, 940 in the respective cells 902, 904, and 906. . In addition, each NodeB 942, 944, 946 and UE 930, 932, 934, 936, 938, 940 may be the UE 122, 132 of FIG. 1 and may perform the methods outlined herein.

  When UE 934 moves from the illustrated location in cell 904 to cell 906, a serving cell change (SCC) or handover occurs, and communication with UE 934 may be referred to as the source cell from cell 904, which may be referred to as the source cell. 906 may be transferred. In UE 934, management of handover procedures may occur at Node B corresponding to each cell, at EPC 880 (FIG. 8), or at another suitable node in the wireless network. For example, during a call with the source cell 904 or at any other time, the UE 934 monitors various parameters of the source cell 904 and various parameters of neighboring cells such as cells 906 and 902. Can do. Further, depending on the quality of these parameters, the UE 934 can maintain communication with one or more of the neighboring cells. During this period, the UE 934 may maintain an active set that is a list of cells to which the UE 934 is simultaneously connected (i.e., a downlink dedicated physical channel DPCH or a fractional downlink dedicated physical channel F-DPCH is currently assigned to the UE 934. Active UTRA cells may constitute the active set). In any case, UE 934 may execute reselection manager 104 to perform the reselection operations described herein.

  Further, the modulation scheme and multiple access scheme used by access network 900 may vary depending on the particular telecommunications standard being introduced. By way of example, the standard may include Evolution-Data Optimized (EV-DO) or Ultra Mobile Broadband (UMB). EV-DO and UMB are air interface standards published by the 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 standard family, and provide broadband Internet access to mobile stations using CDMA. The standard is alternatively Universal Terrestrial Radio Access (UTRA) using other variants of CDMA such as Wideband CDMA (W-CDMA) and TD-SCDMA, Global System for Mobile Communications (GSM®) using TDMA. Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), OFDM 902.11 (Wi-Fi), IEEE 902.16 (WiMAX), IEEE 902.20, and Flash-OFDM using OFDMA. UTRA, E-UTRA, UMTS, LTE, LTE Advanced, and GSM® are described in documents from 3GPP organizations. CDMA2000 and UMB are described in documents from the 3GPP2 organization. The actual wireless communication standard, multiple access technology utilized will depend on the specific application and design constraints imposed on the overall system.

  FIG. 10 is a block diagram of a NodeB 1010 in communication with a UE 1050, which may be one or more of the small cells 110 and / or the coverage optimization manager 112 (FIGS. Figure 2) may be included. For downlink communications, the transmit processor 1020 can receive data from the data source 1012 and receive control signals from the controller / processor 1040. Transmit processor 1020 provides various signal processing functions for data signals and control signals along with reference signals (eg, pilot signals). For example, the transmit processor 1020 may include a cyclic redundancy check (CRC) code for error detection, coding and interleaving to support forward error correction (FEC), various modulation schemes (e.g., binary phase shift keying) (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying modulation (M-PSK), M-quadrature amplitude modulation (M-QAM), etc.) Spreading by rate (OVSF) and multiplication with a scrambling code to generate a series of symbols can be provided. Channel estimation from the channel processor 1044 may be used by the controller / processor 1040 to determine an encoding scheme, modulation scheme, spreading scheme and / or scrambling scheme for the transmit processor 1020. These channel estimates may be derived from a reference signal transmitted by UE 1050 or from feedback from UE 1050. The symbols generated by the transmit processor 1020 are provided to the transmit frame processor 1030 to create a frame structure. The transmit frame processor 1030 creates this frame structure by multiplexing information and symbols from the controller / processor 1040 to obtain a series of frames. This frame is then provided to a transmitter 1032 which performs various signal conditioning functions, including amplification, filtering, and modulation of the frame onto a carrier for downlink transmission over the antenna 1034 over the wireless medium. I will provide a. Antenna 1034 may include one or more antennas, including, for example, a beam steering bi-directional adaptive antenna array or other similar beam technology.

  In UE 1050, receiver 1054 receives the downlink transmission through antenna 1052, processes the transmission and recovers the information modulated onto the carrier. The information recovered by receiver 1054 is provided to receive frame processor 1060, which analyzes each frame and provides information from the frame to channel processor 1094 for data signals, control signals, and references. The signal is provided to receive processor 1070. The receiving processor 1070 then performs the reverse of the processing performed by the transmitting processor 1020 in the NodeB 1010. More specifically, receive processor 1070 de-scrambles and de-spreads the symbols and then determines the most likely signal constellation point transmitted by Node B 1010 based on the modulation scheme. These soft decisions may be based on channel estimates calculated by the channel processor 1094. The soft decision is then decoded and deinterleaved to recover the data signal, control signal, and reference signal. The CRC code is then checked to determine whether the frame has been successfully decoded. The data carried by the successfully decoded frame is then provided to the data sink 1072, which represents an application running on the UE 1050 and / or various user interfaces (eg, displays). The control signal carried by the successfully decoded frame is provided to the controller / processor 1090. If decoding of the frame by the receiving processor 1070 fails, the controller / processor 1090 may also support such a frame retransmission request using an acknowledgment (ACK) protocol and / or a negative acknowledgment (NACK) protocol.

  On the uplink, data from data source 1077 and control signals from controller / processor 1090 are provided to transmit processor 1080. Data source 1077 may represent an application running on UE 1050 and various user interfaces (eg, a keyboard). Similar to the functions described for downlink transmission by NodeB 1010, transmit processor 1080 generates CRC codes, encoding and interleaving to support FEC, mapping to signal sequences, spreading by OVSF, and a series of symbols Various signal processing functions are provided, including scrambling. The channel estimation derived by the channel processor 1094 from the reference signal transmitted by the NodeB 1010 or from the feedback contained in the midamble transmitted by the NodeB 1010 is determined by the appropriate coding scheme, modulation scheme, spreading scheme, and / or Or it can be used to select a scrambling scheme. The symbols generated by the transmit processor 1080 are provided to the transmit frame processor 1082 to create a frame structure. The transmit frame processor 1082 creates this frame structure by multiplexing the information and symbols from the controller / processor 1090 to obtain a series of frames. This frame is then provided to a transmitter 1056, which performs various signal conditioning functions, including amplification, filtering, and modulation of the frame onto the carrier for uplink transmission over the wireless medium through antenna 1052. I will provide a.

  Uplink transmission is processed at NodeB 1010 in the same manner as described for the receiver function at UE 1050. Receiver 1035 receives the uplink transmission through antenna 1034 and processes the transmission to recover the information being modulated onto the carrier. Information recovered by receiver 1035 is provided to receive frame processor 1036, which analyzes each frame and provides information from the frame to channel processor 1044 for data signals, control signals, and references. The signal is provided to receive processor 1037. The reception processor 1037 performs the reverse of the processing performed by the transmission processor 1080 in the UE 1050. The data and control signals carried by the successfully decoded frame can then be provided to the data sink 1039 and the controller / processor, respectively. If a portion of a frame fails to be decoded by the receiving processor, the controller / processor 1040 may also support retransmission requests for such frames using acknowledgment (ACK) and / or negative acknowledgment (NACK) protocols. it can.

  Controllers / processors 1040 and 1090 may be used to direct the operation at NodeB 1010 and UE 1050, respectively. For example, the controllers / processors 1040 and 1090 can provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Computer readable media in memories 1042 and 1092 may store data and software for NodeB 1010 and UE 1050, respectively. A scheduler / processor 1046 at NodeB 1010 may be used to allocate resources to the UE and schedule downlink and / or uplink transmissions of the UE.

  Several aspects of telecommunications systems have been shown with reference to W-CDMA systems. As those skilled in the art will readily appreciate, the various aspects described throughout this disclosure can be extended to other telecommunications systems, network architectures and communication standards.

  As an example, various aspects are extended to other UMTS systems such as TD-SCDMA, High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), High Speed Packet Access Plus (HSPA +) and TD-CDMA. obtain. Various aspects also include Long Term Evolution (LTE) (depending on FDD, TDD, or both modes), LTE-Advanced (LTE-A) (depending on FDD, TDD, or both modes), CDMA2000, Evolution- Data Optimized (EV-DO), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra-Wideband (UWB), Bluetooth, and / or other It can be extended to systems that use appropriate systems. The actual telecommunication standard, network architecture, and / or communication standard utilized will depend on the specific application and design constraints imposed on the overall system.

  In accordance with various aspects of the disclosure, an element or a portion of an element or combination of elements can be implemented in a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gate logic circuits, discrete hardware circuits, and throughout this disclosure There are other suitable hardware configured to perform the various functions described. One or more processors in the processing system may execute software. Software, whether it is called software, firmware, middleware, microcode, hardware description language, or other names, instructions, instruction sets, codes, code segments, program codes, programs, subprograms, software modules , Applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc. should be interpreted broadly. The software may reside on a computer readable medium. The computer readable medium may be a non-transitory computer readable medium. Non-transitory computer readable media include, by way of example, magnetic storage devices (eg, hard disks, floppy disks, magnetic strips), optical disks (eg, compact disks (CDs), digital versatile disks (DVDs)), smart cards Flash memory devices (e.g. cards, sticks, key drives), random access memory (RAM), read only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM) , Registers, removable disks, and any other suitable medium for storing software and / or instructions that can be accessed and read by a computer.

  Computer-readable media can also include, by way of example, carrier waves, transmission lines, and any other suitable media for transmitting software and / or instructions that can be accessed and read by a computer. The computer readable medium may reside within the processing system, may reside outside the processing system, or may be distributed across multiple entities that include the processing system. The computer readable medium may be embodied as a computer program product. By way of example, a computer program product may include a computer readable medium in packaging material. Those skilled in the art will recognize how to best implement the described functionality presented throughout this disclosure, depending on the specific application and the overall design constraints imposed on the overall system.

  It should be understood that the specific order or hierarchy of steps in the methods disclosed represents an exemplary process. It should be understood that the specific order or hierarchy of steps in the method is reconfigurable based on design preferences. The accompanying method claims present elements of the various steps in a sample order, and are not intended to be limited to the specific order or hierarchy presented unless explicitly stated in the claims. .

  The above description is provided to enable any person skilled in the art to implement various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the embodiments shown herein, but are intended to allow the full scope consistent with the language of the claims and reference to a singular element. Is intended to mean "one or more", not "one and only one", unless so specified. Unless otherwise specified, the term “several” means “one or more”. The phrase “at least one of” a list of items means any combination of those items, including a single element. For example, “at least one of a, b or c” means “a”, “b”, “c”, “a and b”, “a and c”, “b and c”, “a, It is intended to include “b and c”. All structurally and functionally equivalent to the elements of the various aspects described throughout this disclosure that will be known or later known to those skilled in the art are expressly incorporated herein by reference and are It is intended to be covered by Also, the content disclosed herein is not intended to be publicly available regardless of whether such disclosure is specified in the claims. Any element of a claim is specified using the phrase “means for” or the element is described using the phrase “steps for” in a method claim Except for the above, no interpretation shall be made under the provisions of Article 112 (6) of the US Patent Act.

100 wireless communication system
102 Core network entities
104 links, backhaul
110 Small cell
112 Coverage Optimization Manager
114 Parameter optimization components
116 Over the air (OTA) link
120 coverage area
130 Coverage Area
140 Coverage Area
210 Backhaul capacity estimation components
212 Target OTA data rate determination components
300 methods
400 system
402 Logical grouping
404 electrical components
406 Electrical components
408 Electrical components
410 memory
500 system
510 HNB
520 User equipment (UE)
530 User residence
540 Internet
550 Mobile operator core network
550 Macrocell mobile network
550 macro network
600 computer devices
602 processor
604 memory
606 communication components
608 data storage
610 User interface components
700 devices
702 bus
704 processor
706 Computer-readable media
708 bus interface
710 transceiver
712 User interface
714 treatment system
800 Long Term Evolution (LTE) network architecture
800 Advanced Packet System (EPS)
802 User equipment (UE)
804 Advanced UMTS Terrestrial Radio Access Network (E-UTRAN)
806 Advanced Node B (eNB)
808 other eNB
820 Home Subscriber Server (HSS)
822 Service provider IP services
862 Mobility Management Entity (MME)
864 Other MME
866 Serving Gateway
868 Packet Data Network (PDN) Gateway
880 Advanced Packet Core (EPC)
900 access network
902 cells
904 cells
906 cells
912 Antenna group
914 Antenna group
916 Antenna group
918 Antenna group
920 antenna group
922 Antenna group
924 Antenna group
926 antenna group
928 Antenna group
930 UE
932 UE
934 UE
936 UE
938 UE
940 UE
942 NodeB
944 NodeB
946 NodeB
1010 NodeB
1012 Data source
1020 Transmit processor
1030 Transmit frame processor
1032 transmitter
1034 Antenna
1035 receiver
1036 Receive frame processor
1037 Receive processor
1039 Data sink
1040 Controller / Processor
1042 memory
1044 channel processor
1046 Scheduler / Processor
1050 UE
1052 Antenna
1054 receiver
1056 transmitter
1060 Receive frame processor
1070 Receive processor
1072 Data sink
1077 Data source
1080 transmit processor
1082 Transmit frame processor
1090 controller / processor
1092 memory
1094 channel processor

Claims (28)

A method for optimizing the coverage area of a small cell,
Estimating the available backhaul capacity of a small cell;
Determining a target over the air (OTA) data rate for the small cell based at least on the estimated available backhaul capacity;
Changing the coverage area of the small cell based at least on the determined target OTA data rate.   The method of claim 1, wherein the coverage area of the small cell is changed by modifying one or more parameters of the small cell.   The method of claim 2, wherein the target OTA data rate is achieved by reducing resource elements (RE) available in the small cell.   3. The method of claim 2, wherein the step of changing the coverage area of the small cell further comprises increasing transmission power per resource element (RE) in the small cell.   3. The method of claim 2, further comprising increasing the transmission power of one or more common channels of the small cell.   The one or more common channels include a common reference signal (CRS), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and a physical downlink control channel (PDCCH). 6. The method of claim 5, wherein the method is selected from a list comprising.   The method of claim 2, wherein the coverage area of the small cell is changed by modifying an operating bandwidth or traffic to pilot ratio of the small cell. A device for optimizing the coverage area of a small cell,
Means for estimating the available backhaul capacity of a small cell;
Means for determining a target over the air (OTA) data rate of the small cell based at least on the estimated available backhaul capacity;
Means for changing the coverage area of the small cell based at least on the determined target OTA data rate.   9. The apparatus of claim 8, wherein the coverage area of the small cell is changed by modifying one or more parameters of the small cell.   10. The apparatus of claim 9, wherein the target OTA data rate is achieved by reducing resource elements (RE) available in the small cell.   10. The apparatus of claim 9, wherein the changing the coverage area of the small cell further comprises increasing transmission power per resource element (RE) in the small cell.   The apparatus of claim 9, further comprising means for increasing transmission power of one or more common channels of the small cell.   The one or more common channels include a common reference signal (CRS), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and a physical downlink control channel (PDCCH). 13. The apparatus of claim 12, selected from a list comprising.   10. The apparatus of claim 9, wherein the coverage area of the small cell is changed by modifying an operating bandwidth or traffic to pilot ratio of the small cell. A computer program product for optimizing the coverage area of a small cell,
Estimating the available backhaul capacity of a small cell;
Determining a target over the air (OTA) data rate for the small cell based at least on the estimated available backhaul capacity;
A computer program product comprising a non-transitory computer readable medium comprising code executable by a computer to change the coverage area of the small cell based at least on the determined target OTA data rate.   The computer program product of claim 15, wherein the coverage area of the small cell is changed by modifying one or more parameters of the small cell.   17. The computer program product of claim 16, wherein the target OTA data rate is achieved by reducing resource elements (RE) available in the small cell.   17. The computer program product of claim 16, wherein the changing the coverage area of the small cell further comprises increasing transmission power per resource element (RE) in the small cell.   The computer program product of claim 16, further comprising code for increasing transmission power of one or more common channels of the small cell.   The one or more common channels include a common reference signal (CRS), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and a physical downlink control channel (PDCCH). The computer program product of claim 19, selected from a list comprising.   17. The computer program product of claim 16, wherein the coverage area of the small cell is changed by modifying the small cell's operating bandwidth or traffic to pilot ratio. A device for optimizing the coverage area of a small cell,
A backhaul capacity estimation component to estimate the available backhaul capacity of a small cell;
A target OTA data rate determination component for determining a target over the air (OTA) data rate of the small cell based at least on the estimated available backhaul capacity;
A parameter optimization component for changing the coverage area of the small cell based at least on the determined target OTA data rate.   23. The apparatus of claim 22, wherein the parameter optimization component is further configured to change the coverage area of the small cell by modifying one or more parameters of the small cell. .   24. The apparatus of claim 23, wherein the target OTA data rate determination component is further configured to achieve the OTA data rate by reducing resource elements (RE) available in the small cell. .   The parameter optimization component is further configured to change the coverage area of the small cell by increasing transmit power per resource element (RE) in the small cell. The device described.   24. The apparatus of claim 23, wherein the parameter optimization component is further configured to increase transmission power of one or more common channels of the small cell.   The one or more common channels include a common reference signal (CRS), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and a physical downlink control channel (PDCCH). 27. The apparatus of claim 26, selected from a list comprising.   23. The apparatus of claim 22, wherein the coverage area of the small cell is changed by modifying an operating bandwidth or traffic to pilot ratio of the small cell.

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